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Commit246be30

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Add mention of performance impact on LIKE of non-C locales.
1 parenta2a5526 commit246be30

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3 files changed

+34
-23
lines changed

3 files changed

+34
-23
lines changed

‎doc/src/sgml/charset.sgml

Lines changed: 15 additions & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -1,4 +1,4 @@
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<!-- $PostgreSQL: pgsql/doc/src/sgml/charset.sgml,v 2.47 2004/12/27 22:30:10 tgl Exp $ -->
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<!-- $PostgreSQL: pgsql/doc/src/sgml/charset.sgml,v 2.48 2005/01/04 00:05:44 momjian Exp $ -->
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33
<chapter id="charset">
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<title>Localization</>
@@ -189,10 +189,10 @@ initdb --locale=sv_SE
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</sect2>
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<sect2>
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<title>Benefits</>
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<title>Behavior</>
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<para>
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Locale support influencesin particularthe following features:
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Locale support influences the following features:
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<itemizedlist>
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<listitem>
@@ -202,6 +202,13 @@ initdb --locale=sv_SE
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</para>
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</listitem>
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<listitem>
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<para>
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The ability to use indexes with <literal>LIKE</> clauses
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<indexterm><primary>LIKE</><secondary>and locales</></indexterm>
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</para>
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</listitem>
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<listitem>
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<para>
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The <function>to_char</> family of functions
@@ -211,9 +218,11 @@ initdb --locale=sv_SE
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</para>
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<para>
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The only severe drawback of using the locale support in
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<productname>PostgreSQL</> is its speed. So use locales only if
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you actually need them.
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The drawback of using locales other than <literal>C</> or
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<literal>POSIX</> in <productname>PostgreSQL</> is its performance
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impact. It slows character handling and prevents ordinary indexes
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from being used by <literal>LIKE</>. For this reason use locales
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only if you actually need them.
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</para>
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</sect2>
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‎doc/src/sgml/ref/initdb.sgml

Lines changed: 14 additions & 13 deletions
Original file line numberDiff line numberDiff line change
@@ -1,5 +1,5 @@
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<!--
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$PostgreSQL: pgsql/doc/src/sgml/ref/initdb.sgml,v 1.32 2004/08/01 06:19:18 momjian Exp $
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$PostgreSQL: pgsql/doc/src/sgml/ref/initdb.sgml,v 1.33 2005/01/04 00:05:45 momjian Exp $
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PostgreSQL documentation
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-->
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@@ -54,21 +54,22 @@ PostgreSQL documentation
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</para>
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<para>
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<command>initdb</command> initializes the database cluster's
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default locale and character set encoding. Some locale categories
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are fixed for the lifetime of the cluster, so it is important to
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make the right choice when running <command>initdb</command>.
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Other locale categories can be changed later when the server is
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started. <command>initdb</command> will write those locale
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settings into the <filename>postgresql.conf</filename>
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configuration file so they are the default, but they can be changed
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by editing that file. To set the locale that
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<command>initdb</command> uses, see the description of the
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<option>--locale</option> option. The character set encoding can
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<command>initdb</command> initializes the database cluster's default
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locale and character set encoding. Some locale categories are fixed
59+
for the lifetime of the cluster. There is also a performance impact
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in using locales other than <literal>C</> or <literal>POSIX</>.
61+
Therefore it is important to make the right choice when running
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<command>initdb</command>. Other locale categories can be changed
63+
later when the server is started. <command>initdb</command> will
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write those locale settings into the
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<filename>postgresql.conf</filename> configuration file so they are
66+
the default, but they can be changed by editing that file. To set the
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locale that <command>initdb</command> uses, see the description of
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the <option>--locale</option> option. The character set encoding can
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be set separately for each database as it is created.
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<command>initdb</command> determines the encoding for the
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<literal>template1</literal> database, which will serve as the
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default for all other databases.To alter the default encoding use
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default for all other databases. To alter the default encoding use
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the <option>--encoding</option> option.
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</para>
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‎doc/src/sgml/runtime.sgml

Lines changed: 5 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -1,5 +1,5 @@
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<!--
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$PostgreSQL: pgsql/doc/src/sgml/runtime.sgml,v 1.299 2004/12/26 23:06:56 tgl Exp $
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$PostgreSQL: pgsql/doc/src/sgml/runtime.sgml,v 1.300 2005/01/04 00:05:44 momjian Exp $
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-->
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<Chapter Id="runtime">
@@ -144,9 +144,10 @@ postgres$ <userinput>initdb -D /usr/local/pgsql/data</userinput>
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that can be found in <xref linkend="locale">. The sort order used
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within a particular database cluster is set by
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<command>initdb</command> and cannot be changed later, short of
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dumping all data, rerunning <command>initdb</command>, and
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reloading the data. So it's important to make this choice correctly
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the first time.
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dumping all data, rerunning <command>initdb</command>, and reloading
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the data. There is also a performance impact for using locales
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other than <literal>C</> or <literal>POSIX</>. Therefore, it is
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important to make this choice correctly the first time.
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</para>
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</sect1>
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